4-hydroxytest is essentially anon armoatizing testosterone very similar to the chemical formula of formestanre. I think the difference lies in one of tthe carbon atoms or lack therof. It would be a good anabolic/androgenic without the risk of estrogenic sideaffects. According to PA only he knows the burn free 1-test formula so I think Animals cyp may be pain less but not pain free if you get my menaning. i believe he on his board says the pain is bearable

bumping this... I'm new here and was looking for info specifically about 4-Hydroxy. It (Promatrix's) is sold at a supp store near me and the guys rave about it, claiming it's better than 1-test, but I can't find info on it on the web.